d day and normandy

Sounds like a great trip, Gary! There is a lot of advice specific to that question if you want to search the forum. I'll just add that we chose to train to Caen and rent a car for a tour of the beaches, the American cemetery and then down to Mont st Michele. If you have a car, you may consider staying in this incredible B&B chateau we stayed in. Very close to Omaha and the American cemetery. It one of the oldest in the area, yet very comfortable and delicious food! The home was occupied by Nazi officers and the current owners told us about its history-a really memorable experience! Le Chateau d'Asnieres en Bessin
https://www.tripadvisor.com/Hotel_Review-g2048911-d2284022-Reviews-Le_Chateau_d_Asnieres_en_Bessin-Asnieres_en_Bessin_Calvados_Basse_Normandie_Normandy.html

I'm a big fan of taking a tour rather than attempting the do-it-yourself approach for the invasion sites. (Seeing the museums on your own is a really good idea; I've never seen a tour spend as much time as I would like in any museum.)

There are quite a few companies doing tours of the D-Day sites. Most start from Bayeux. I used and was happy with Overlord Tours; I believe the current price is just over 100 euros per person for a full-day tour. The company uses vans, so you're not on a big bus. That may be true of all the other Bayeux-based companies; I'm not sure. Overlord gets a lot of positive mentions on this forum.

Dale Booth is also highly recommended here. I don't know what those tours cost.

The Peace Museum in Caen operates tours, but I believe they last just part of the day, with the rest of the time spent at the museum. Personally, I think a partial-day tour is a poor idea. The invasion sites are spread out and some distance from Bayeux. If you have less than a full day, a large part of your tour time will actually be spent driving back and forth from Bayeux and between the sites.

I liked the Caen Museum a lot, but opinion is sharply divided on it. It is large, crowded (pre-pandemic) and expensive. It covers the lead-up period to the war and the Cold War as well as WWII itself. That's more than a lot of people are interested in and have time for, apparently.

There are quite a few smaller museums in Normandy with narrower focus. My Overlord Tour allowed just about enough time in St-Mere-Eglise to see the Airborne Museum there if one didn't take time for a sit-down lunch. I found that museum rather old-fashioned, but the information was good. The invasion museum in Bayeux is modern and pretty comprehensive. If your main interest is in the Normandy invasion (as opposed to WWII in general) and you only have a few hours to spend, I think the Bayeux museum is a better choice than the one in Caen.

There's a good, modern museum about civilian life during the war (including the Resistance) in Falaise. There are some museum-like displays at the Visitor Center of the American Cemetery. (My tour stop there really allowed time to see some of the VC or some of the Cemetery, not both.) Other posters have mentioned additional museums in Normandy, but I didn't get to them.

I think Bayeux is a more congenial city to stay in than Caen. In addition to its being the starting point for most of the D-Day tours, you have a nice historic center to explore, the cathedral and the Bayeux tapestry. Caen, as a major seaport, was nearly obliterated during the war, though it does have a few remaining historic structures.

gary, you haven’t made clear whether you plan to spend the night, or if you will rent a car in Caen. As noted this subject has a big archive here. (Search box top center) For example:
https://community.ricksteves.com/travel-forum/france/day-trip-from-paris-to-d-day-beaches-acf8ace3-7773-4e57-b464-b178dcd45e1f

Ironic that this is posted today. It was exactly this moment that we were flying to Paris then taking a train to Bayeux. We stayed 2 nights in Bayeux and did a Dale Booth tour. We stayed at Hotel Bayeux and Dale picked us up the following morning for our full day private tour. I cannot praise him enough for his WW2 knowledge. He went in such great depth and detail at every location we went to. If you are looking to do a one or two day tour, I would highly recommend Dale. It was well worth the price (around $700 USD, I think!) for our family of four!
https://dboothnormandytours.com/

An excursion with an overnight stay will be more rewarding so you can take a full day around the beaches. Don't write off Caen as your base as it is bigger with more hotels and restaurants to choose from. The commute to Bayeux is quick and easy. A bit of time strolling around William the Conqueror's fortress castle is worth it, right in the centre of Caen. My knowledge of tours is outdated by now but you should know that the routes are somewhat different for those wanting to see the British Commonwealth beaches and the Canadian museum, plus possibly the location of the critical tank battles around Caen after the landing.

If you have your own rental car, be aware of the bus vs. car parking lots by the Normandy beaches. The bus tours use the bus parking lots, but these aren't marked in any obvious way. What's visible -- but not obvious if no one tells you -- is that the lots with a horizontal bar (preventing high vehicles like buses) are for cars. If you park a car in the bus lot, the bus drivers will be very unhappy.

We didn't know this and got blocked in by a bus. The driver refused to move until all the passengers were back aboard, and then my husband had to do a sort of Tiananmen Square standoff with the next incoming bus to let me back out of our space.

Hi Gary - I’ve been to Janesville many times, having relatives in nearby Delavan!

I’ve said this many times on the forum: give yourself time in Normandy or save it for another trip. Going there as a day trip from Paris will be an expensive, exhausting blur.

Give yourself a minimum of 3 days (ideally 4 or 5). Stay in a centrally located town like Bayeux or St. Mere Eglise. If you have the budget for a full-day private tour guide, please invest in one. It is well, well worth it. Build in time for the Utah Beach Museum, American and German cemeteries, smaller museums (Arromanches has an interesting one), Bayeux Tapestry, and so many other options. Bayeux has a fantastic weekly farmers market with delicious food stalls.

It’s a large, lovely region. Carve out enough time to savor it. There’s even local cideries and Calvados distilleries to visit. PM me if you have questions.

And if you decide to just hang in Paris, that would be amazing too (be sure to hit up the incredible Berthillon ice cream parlor on Ile Sainte Louis and spend a day exploring Montmartre)!